Filming and coating composition



, Patented June 16, 1936 v UNITED STATES PATENT- OFFICE FILMING 1103 2122; oomosrriou I I Harold A. Levey, New Orleans, La.

No Drawing. Application July 2'7, 1931,

Serial No. 553,477

13 claims. (or. 106-40) The present invention relates to films of cellulike bodies \such as the natural vegetable and lose derivatives, either self sustaining or emanimal waxes and the higher fatty acids. The ployed as protective coatings and to compositions organic derivatives of cellulose have not hitherto for producing the same. It will be fully underbeen regarded asavailable for use with such 5 stood from the following description, wherein vawaxes by reason of the low solubility compatibil- 5 rious embodiments of the invention are specifiity or miscibility of waxes therewith; For excally set forth. ample, various wax-like bodies, such a'sbairberry, Films of the various cellulose plastic compp rm ce i, and vari hi h r f y acids such sitions, such as viscose, cellulose acetate, celluas palmitic acid, stearic acid, lauric acid, myristic lose nitrates, cellulose ethers and the like, as acid and the like may be employed. '1 have found 10 hitherto made, are not inherently moisture-transthat the incorp into the fi r t e 11 mission resistant. Thus, I have found that a face thereof of small proportions of such waxviscose film of approximately 0.001 inch thickl ke b es, say in general less than and orness transmits approximately 60 grams of water dlnarily from 0.5 to 2% reduces the moisture per 100 square inches of exposed surface per 24 transmission through the film to to 15% or 15 hours at '70 R, 'th a relative humidity of 100% less of that which it would normally have. Thus, on one side and'50% on the other side of the film. by operating in accordance with the present in- Similarly, a film of pure cellulose acetate of the vention, I have been able toproduce films which, same thickness and under the same conditions in a thickness of 0.001inch, show a moisture transmits, for the same area, from 40 grams to 55 transmission of 2 to 5 grams per 100 square grams of water per 24 hours, depending upon the inches per 24 hours under the conditions of the viscosity of the cellulose acetate employed, higher test hereinbefore described. viscosity products showing the lower moisture In general,1prefer to employ the wax-like body 25 transmission. The moisture transmissionof the in the production of a homogeneous film with cellulose acetate film may be somewhat reduced, the cellulose ester material, suitably in conjuncsay by about 20% by the incorporation of plastion with plasticizers and with natural or synticizers of a water-insoluble, non-hygroscopic thetic resinous materials preferably non hygrotype; and the moisture transmission may likescopic in character; or the use of separate plaswise be reduced by a similar or slightly larger ticizers maybe eliminated, for example, by em- 30 amount by incorporating into the film of the ploying synthetic resinous materials having a plastic natural and synthetic resins. In general, plastici'zing action. For example, I may employ however, the films or coatings produced from resinous bodies of the soluble, fusible, phenolaldesuch cellulose plastic compositions are not sathyde or urea-aldehyde types compatible with celisfactory as protective agents for food products, lulose acetate or other cellulose derivative cm- 35 tobacco and the like. Efforts have hitherto been ployed and particularly those incorporating fatty made to further improve the resistance of the compounds or fatty acids or acetylated derivafilm to moisture transmission, by the use of comtive thereof, such as are now employed as resinous posite films for example, but these are in general bodies and plasticizers in cellulose lacquers, cel- 40 unsatisfactory or expensive. It has been p'arlulose plastics and the like, forexample, the com- 40 ticularly difilcult hitherto to secure films consistmercial product known as Bakelite resin plasing mainly of the organic derivatives of cellulose ricizcr XR-926. v having low moisture transmission properties, the In preparing a (com osition produced in aceffort hitherto made involving the use of composcordance with the present invention, the cellulose ite films, one constituent of which includes a ester body, with asuitable proportion of the wax- 45 7 highly inflammable nitro-cellulose compound of like material, as hercinbefore set forth, together relatively great wax solvent power. I with suitable plasticizers or resinous bodies or I have discovered that the resistance tomoisboth are incorporated into a suitable solvent or ture transmission of cellulose plastic films of the solvent mixture. While the ordinary solvents type normally transmitting moisture readily may be employed-,\such as ethylene'glycol methyl 50 (that is, having a moisture transmissibility of 25 f ether, the acetic ester of the mono-ethyl ether of to 30 grams or more per 100 square inches per 24 "-{ethylene glycol, acetone, or. the like, or mixtures hours under the conditions hereinbefore set thereof with higher boiling solvents. It is preforth) may be markedly increasedbyincorporatfefrred that the use of very low boiling solvents F ing into the film varying proportions of waxalone be avolded,asin their evaporation they tend 55 to produce a greater is desired. I found as porosity of the film than particularly suitable, that to 25%. The ordinary resins such as glyceryl-phthalate resins or the like may be used. However, I prefer to employ a permanently soluble, fusible resin of the phenol aldehyde or phenol-methylene type, suitbefore described.

A preferred composition in accordance with the present invention is one containing the following constituents (exclusive of solvents):

Per cent Cellulose acetate Bayberry wax 1 Soluble phenol-aldehyde resinoid; 19

by weight of the latter.

A second specific formula prepared in accordance with the present invention is-as follows:

Per cent Cellulose acetate 80 Palmitic acid 2 Soluble phenol-aldehyde resinoid 18 These constituents may be dissolved in solvent constituents such as are described in connection hitherto produced.

In the above examples, other resinous bodies, such as a urea-aldehyde resinoid or a compatible formates, propionates, benzoates, stearates, and of mixtures thereof may be employed, suitable solventsbeing employed. Small proportions of therewith, as desired.

If desired, films produced in accordance with the present invention may ture transmission therethrough.

The moisture transmission of cellulose plastic films, as hitherto prepared and as ordinarily inbefore described. In order to effect such surface application of the wax-like body, the latter, which may be stearic acid, like or mixtures thereof is half to 2%, like bodies.

to 60 0., the temperature being substantiallyberivatives, paper sheets, bakelite sheets an d gther more or less absorptive materials.

The solvent for the wax employed in the surwax content of the solution being about the same as hereinbefore set forth. The solution is used at a suitable temperature, say 40 C. With such solutions, the surface of the cellulose acetate or other cellulose plastic sheets or films is slightly attacked and the wax-like compound is intimately incorporated with the surface material of the sheet. The application of such solutions may be followed by a heating and wiping treatment as hereinbefore described, if desired.

The present invention may be employed in connection with the preparation of films, sheets and the like from various cellulose plastics having a high moisture transmission rate such as the cellulose acetates, formates, butyrates, propionates and benzoates, and the cellulose methyl and ethyl ethers, the amino compounds and other cellulose derivatives. The films prepared in accordance with the present invention, when self sustaining, may be employed as wrappings for food products, tobacco products, pharmaceuticals and the like or in general where high moisture transmission resistance is desired, and when in the form of coating films are valuable where resistance to passage of moisture is needed, such as a coating composition and film for sheets of viscose,- gelatin, casein, starch, etc. The films and coatings prepared in accordance with the present invention are particularly valuable as electrical insulating materials or for the protection of electrical insulating materials, since they have of themselves excellent dielectric qualities.

1. A transparent film-forming base comprising approximately 80% cellulose acetate, 18 to 19% soluble phenol aldehyde resin, and the balance a compound of the class consisting of bayberry wax and palmitic acid.

2. A film-forming. composition comprising a base comprising approximately 80% cellulose ace tate, 1% palmitic acid, 19% soluble phenol aldehyde resin, and a solvent for said base.

3. A film-forming composition comprising a base comprising approximately 80% acetate, 2% palmitic acid and 18% soluble phenol aldehyde resin, and a solvent for the base.

4. As an article of commerce, a transpa ent film-forming composition comprising a major portion of an organic derivative of cellulose, a minor portion of a soluble phenol aldehyde resin, and a compound of the class consisting of bayberry wax and palmitic acid, said compound being present in the amount of A; to 2% by weight of the weight of the cellulose derivative and the phenol aldehyde resin; and a solvent therefor.

5. The film-forming composition as set forth in claim 4, in which the cellulose derivative is cellulose acetate.

6. The film-forming composition as set forth 20 in claim 4, in which the compound is bayberry wax.

'7. The film-forming composition as set forth in claim 4, in which the compound is palmitic acid.

8. A transparent homogenous self-sustaining flexible film, comprising approximately 80 parts cellulose acetate, 19 parts of a soluble phenol aldehyde resin and 1 part bayberry wax.

9. A transparent homogenous self-sustaining flexible film, comprising approximately 80 parts cellulose acetate, 2 parts palmitic acid and 18 parts soluble phenol aldehyde resin.-

10. A homogenous transparent self-sustaining flexible film, comprising approximately 80% cellulose acetate, 18 to 19% soluble phenol aldehyde resin and the balance a compound-of the class consisting of bayberry wax and palmitic acid.

11. A homogenous transparent self-sustaining flexible film comprising a major proportion of 40 cellulose acetate, a minor proportion of a soluble phenol aldehyde resin and to 2% of the weight of the combined resin and acetate of a compound of the classconsisting of palmitic acid and bayberry wax. d

12. A film as in claim 11 in which the compound is palmitic acid.

13. A film as in claim 11 in which the compound is bayberry wax.

HAROLD A. LEVEY.

cellulose 5 V 

